In Fig. REF  one can observe two main branches, related to the transition density; the solid (dashed) curves correspond to the \(n_{\mathrm {tr}}=1.5n_s\)  (\(n_{\mathrm {tr}}=2n_s\) ) case. In each branch, there are bifurcations in the families of EoSs, in analog to each speed of sound boundary condition. The higher the speed of sound, the lighter the representing color of the curves in the figure. The purple solid horizontal line, with the shaded region, indicates the estimation of the recently observed massive compact object of Ref. [1]}. As Fig. REF  shows, the branch of EoSs with \(n_{\mathrm {tr}}=1.5n_s\)  provides stiffer EoSs compare to the \(n_{\mathrm {tr}}=2n_s\)  branch. The EoSs of the \(n_{\mathrm {tr}}=1.5n_s\)  case are more likely to provide such a massive non-rotating neutron star, than the \(n_{\mathrm {tr}}=2n_s\)  case in which three EoSs of the total sum lie outside of the shaded region. Especially, between the same kind of transition density \(n_{\mathrm {tr}}\)  the EoSs with higher speed of sound bounds lead to higher values of neutron star mass and radius, hence a high bound of the speed of sound (even more close to the causality as the transition density is getting higher) is needed for the description of such a massive compact object.
